Sharif Digital Repository

A method of joining dissimilar metals in the semi solid state is presented. By this method bonding of Stainless steel and semisolid aluminum alloy took place in this research. By usage of thermomechanical treatment, dendritic microstructure of cast aluminum alloy changed to globular structure. The experimental process of bonding occurred at semisolid temperature stage of aluminum alloy in a predesigned mold by using a pressure equipment. The relationship between interfacial shear strength and solid fraction of aluminum alloy, bonding pressure and time of keeping pressure were studied by method of orthogonal experiment. By the usage of Taguchi method in designing experiments, plurality of... 

Today, many organizations have come to believe that one of their most valuable assets is their product and/or service brands. In today's complex and challenging world, we are all faced with increasing options and decreasing time for decision making and making our choices. On this basis, the ability of brands to simplify decision making for customers, reduce risks and define expectations for them is invaluable. In recent decades, the issue of branding has become an important part of business strategy. Branding plays an important and special role in service organizations, because powerful brands have a significant impact on customers' decisions and perceptions of the brand. In this research,... 

In this thesis, we will examine the issue of managing airlines' income and determining the appropriate policies for storing accommodation for different classes in the seats of a flight. Most airlines use a nesting structure to allocate seats, in which access between classes is possible, but only the higher class can access all the seats in the subclass. It is assumed that this structure and allocation process increase company revenue, but the problem is that the chances of staying in the seat will increase in the hope of higher demand and higher risk of corporate income reduction.With the goal of providing a way to determine the optimal classroom dynamically, this study, for the first... 

This thesis deals with the construction of software tools necessary to calculate the position and orientation of the robot. The aim of this project is to use accelerometer, gyroscope, magnetometer and GPS sensors; Determine the position and orientation of the robot where the mobile phone is located. The proposed sensors are used to measure acceleration, angular velocity and magnetic field in 3 axes, respectively. GPS is also a system for calculating the position using signals received from satellites. To do this, an Android application has been designed and written in Java. The sensor information is collected by the software designed in the mobile phone and after proper coding is sent to a... 

In this project, using experimental results for permeation of gases H2, He, N2, and CO on a microporous membrane (the applied sample was a ceramic membrane) and modified equations, pore diameter, tortuosity, and porosity were determined for this type of membrane. Furthermore, pore diameter, critical volume, and characteristic energy of a carbon molecular sieve membrane were calculated using experimental data for CO2 adsorption on this type of membrane. Diffusivities of CO2, N2, and Ar were also calculated by means of the uptake, time lag/adsorption, and permeability/adsorption tests on carbon molecular sieve membranes utilizing experimental data obtained for this type of membranes and the...